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At our cabin the local and only gas station just quit selling 92 octane fuel this spring Cry.gif They said they did not sell enough of it to warrant carrying it, the problem know is what to use in my BU. According to Indmar the 05 HH needs min. 92 octane fuel. Having the gas station there is so convenient it is 2 minutes from my cabin, my next alternative is probably 20 minutes away. What would you do ?option 1 use the 87 octane fuel they carry and add octane additive or option 2 travel the 20 minutes for the 92 octane fuel. ;)

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Chauncemaster
At our cabin the local and only gas station just quit selling 92 octane fuel this spring Cry.gif They said they did not sell enough of it to warrant carrying it, the problem know is what to use in my BU. According to Indmar the 05 HH needs min. 92 octane fuel. Having the gas station there is so convenient it is 2 minutes from my cabin, my next alternative is probably 20 minutes away. What would you do ?option 1 use the 87 octane fuel they carry and add octane additive or option 2 travel the 20 minutes for the 92 octane fuel. ;)

I know my bu likes 87 Octane just fine and that is all I use since I see no difference with other octanes. I know many people use a whole range of octanes in their Bu's but I've never heard from anyone who actually had problems with knocking or pre-mature explosions when using 87 even though indmar reccomends 89

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LS-One

I read the fine print on every octane booster in the store one day the best one raised the fuel .08 % sounds like you are screwed unless there is an airport around.

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andyb

For the long term I would give the Hammy what it wants.

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superjet

What would 5 gallons of race fuel or avgas do to your octane?

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NorCaliBu
What would 5 gallons of race fuel or avgas do to your octane?

If my calculations are correct...

10 gallons of 104 octane race gas added to 25 gallons of 87 octance reg unleaded would give you 35 gallons of 91.85 octane fuel.

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Boomer

Where is the requirement for the HH listed as 92 octane? In my Indmar manual it says the LS1 and LQ9 need 93, and all others 89.

Is there a newer manual than they have on their web site?

BTW, race gas (leaded or unleaded) is damn expensive. Over $4 a gallon at every dragstrip I've been to, and that was a couple years back before gas prices skyrocketed. It will raise your octane though if you mix it. Octane boosters are a joke, as someone mentioned they raise the octane a few tenths.

AV gas has extremely high levels of lead, even the "low-lead" variety. No O2 sensors or cats in a boat to worry about messing up with lead, but still don't think I'd want to use leaded gas.

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NorCaliBu
BTW, race gas (leaded or unleaded) is damn expensive. Over $4 a gallon...

There's a station in Wheatland (on Hwy 65) that's at $4.09 / gal for 104 race gas. 10 gallons of race + 25 gallons of reg ($2.39) = 2.87 / average cost per gallon. Not saying it's worth the headache.... Crazy.gif

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stewart

If you decide to go AVgas or race gas, make sure you use unleaded.

That said, I would try a tank of 87 and see what happens. You can always just bring in 92/93 octane, 2 x 5 gallons and then top off with 87 as well.

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LSV Footin
Where is the requirement for the HH listed as 92 octane? In my Indmar manual it says the LS1 and LQ9 need 93, and all others 89.

Is there a newer manual than they have on their web site?

BTW, race gas (leaded or unleaded) is damn expensive. Over $4 a gallon at every dragstrip I've been to, and that was a couple years back before gas prices skyrocketed. It will raise your octane though if you mix it. Octane boosters are a joke, as someone mentioned they raise the octane a few tenths.

AV gas has extremely high levels of lead, even the "low-lead" variety. No O2 sensors or cats in a boat to worry about messing up with lead, but still don't think I'd want to use leaded gas.

I read it on indmar's web site

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SacRiverRat

Wouldn't worry about it. Fill it with 91/92 whenever you can

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OGGIE

I never bought gas at the lake all last summer,even though there is a gas dock 1 min. from our place.I have 4-5gallon gas cans and fill them at home with marked gas before we head to the lake.Take the empty's home and refill them for next week.I did it this way because I saved 14cents a litre and it is 92 octane instead of only 87 oct they sell at the lake.

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SacRiverRat

Boy - sure doesn't seem worth the time or effort... especially with the higher fuel consumption of the bigger boats. If there isn't decent gas at the lake, that is one thing. The time spent filling cans, pouring into the boat, hauling, risk of spilling etc.. sure doesn't seem worth the small cost savings, or few octane points

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SunriseH2OSkier

Really not a big deal to burn 87 in your HH. You've got a knock sensor that will retard timing to prevent knock. It will cut back a little on your performance (torque/hp), but most people won't notice the difference. If you want more detail on what a knock sensor does for you, check out this thread on WSR. Tommy boy and I had a bit of a 'discussion' about it. Crazy.gif

If I were you I would run the 87, and make an occasional trip for a tankful of the 92 (just to make myself feel better).

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LS-One
I read the fine print on every octane booster in the store one day the best one raised  the fuel .08 %  sounds like you are screwed unless there is an airport around.

Sorry I was using fuzzy math, what I meant to say was octane boosters raised the octane level 8/10's of one octane point

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LS-One
If you decide to go AVgas or race gas, make sure you use unleaded.

That said, I would try a tank of 87 and see what happens.  You can always just bring in 92/93 octane, 2 x 5 gallons and then top off with 87 as well.

Indmar told me leaded gas would do no harm

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Headhunter 2317

My baby loves a tank of Premium. Not every time, but maybe every other time.

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stewart
If you decide to go AVgas or race gas, make sure you use unleaded.

That said, I would try a tank of 87 and see what happens.  You can always just bring in 92/93 octane, 2 x 5 gallons and then top off with 87 as well.

Indmar told me leaded gas would do no harm

Maybe no harm to the engine, but definitely harm to the lake Crazy.gif

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LS-One
If you decide to go AVgas or race gas, make sure you use unleaded.

That said, I would try a tank of 87 and see what happens.  You can always just bring in 92/93 octane, 2 x 5 gallons and then top off with 87 as well.

Indmar told me leaded gas would do no harm

Maybe no harm to the engine, but definitely harm to the lake Crazy.gif

Its lead, it sinks to the bottom

:lol:

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denjoe

I am no mechanic, but as an engineer when you write an engineering specification, you always calculate safety factors into your spec. Indmar is publishing 89 octane, I can't imagine any benefit to 91+ octane. If Indmar felt it would improve their performance specs. don't you think they would require 89 for the 320 & Monsoon motor?

I will happily put 89 in whenever possible.

Joe

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andyb

In a post of mine above, I mentioned octane ratings of 91 and 96 in New Zealand. It seems we use a different calculation in line with Europe & Australasia and hence some confusion. Obviously, it will be similar juice to the 87 and 91 octane fuels in US.

The Shell site in Canada explains: "Technically there are three different "octane numbers" associated with every gasoline. The Research Octane Number, or RON, is measured under fairly easy test conditions. The Motor Octane Number, or MON, is a tougher test measured at higher engine speed and temperature.

The value that relates most closely to actual driving conditions is the average of these two values: Road Octane Number = (RON + MON)/2. This Road Octane value is the one referred to in Shell stations: Shell Bronze gasoline has an octane rating of 87, Shell Silver is 89 and Shell Optimax Gold is 91.

Occasionally, less scrupulous Canadian gasoline outlets will use the confusion of these different octane measurements to exaggerate their octane rating claims, by advertising their fuel's Research Octane Number - which will be higher than the Road Octane Number. It is also a common practice in many European countries to advertise the Research Octane Number on their pumps, so you may see unexpectedly high octane values when travelling abroad. In Canada, motorists should always be sure that the octane number a vendor advertises is its Road Octane value, not its RON."

Info overload but the idea of using higher octane is that it burns progressively rather than exploding prematurely and damaging the engine.

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